/* Premium design variables */
:root {
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Radii */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Brand colours (theme-agnostic) */
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-primary-light: rgba(59, 130, 246, 0.18);
  --color-primary-shadow: rgba(59, 130, 246, 0.25);

  --color-remaining: #f59e0b;
  --color-remaining-hover: #d97706;
  --color-remaining-light: rgba(245, 158, 11, 0.18);
  --color-remaining-shadow: rgba(245, 158, 11, 0.25);

  /* ── DARK theme (default) ── */
  --bg-app: #0b0f1a;
  --bg-card: #111827;
  --bg-input: #1e293b;
  --bg-button-hover: rgba(59, 130, 246, 0.12);
  --bg-progress-track: #1e293b;
  --bg-header: #111827;

  --border-primary: #1e293b;
  --border-secondary: #1a2234;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #475569;
  --text-title: #e2e8f0;

  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px -1px rgba(0, 0, 0, 0.5), 0 2px 6px -2px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 24px -3px rgba(0, 0, 0, 0.55), 0 4px 8px -4px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 40px -5px rgba(0, 0, 0, 0.6), 0 8px 16px -6px rgba(0, 0, 0, 0.5);

  --remaining-track-bg: rgba(245, 158, 11, 0.08);

  /* Theme-toggle icon */
  --theme-icon: "☀️";
}

/* ── LIGHT theme ── */
[data-theme="light"] {
  --bg-app: #f8fafc;
  --bg-card: #ffffff;
  --bg-input: #f8fafc;
  --bg-button-hover: #eff6ff;
  --bg-progress-track: #f1f5f9;
  --bg-header: #ffffff;

  --border-primary: #e2e8f0;
  --border-secondary: #f1f5f9;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-title: #1e293b;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

  --remaining-track-bg: #fef3c7;

  --theme-icon: "🌙";
}

/* ── Base resets & styles ── */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  min-height: 100vh;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease;
}

::selection {
  background-color: var(--color-primary-light);
  color: var(--color-primary-hover);
}

/* ── Layout Container (Mobile Center) ── */
.app-container {
  max-width: 28rem;
  margin: 0 auto;
  background-color: var(--bg-card);
  min-height: 100vh;
  min-height: 100dvh;
  box-shadow: var(--shadow-xl);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease;
}

/* ── Header ── */
.app-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-header);
  position: sticky;
  top: 0;
  z-index: 10;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.app-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--text-title);
  transition: color 0.3s ease;
}

.btn-toggle-settings {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-primary);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
}

.btn-toggle-settings:hover {
  color: var(--color-primary-hover);
  background-color: var(--bg-button-hover);
}

/* ── Theme Toggle Button ── */
.btn-theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-primary);
  background-color: var(--bg-input);
  cursor: pointer;
  transition: all 0.25s ease;
  font-size: 1rem;
  line-height: 1;
  padding: 0;
  flex-shrink: 0;
}

.btn-theme-toggle:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
  transform: rotate(20deg) scale(1.1);
}

.btn-theme-toggle:active {
  transform: rotate(20deg) scale(0.95);
}

/* Icon inside toggle — changes via CSS variable */
.btn-theme-toggle::after {
  content: var(--theme-icon);
}

/* ── Main Area ── */
.app-main {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  background-color: var(--bg-app);
  display: flex;
  flex-direction: column;
  gap: 2rem;
  transition: background-color 0.3s ease;
}

/* ── Animations ── */
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(1rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  animation: fadeIn 0.5s ease-out forwards;
}

.animate-slide-in {
  animation: slideInUp 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* ── Settings view ── */
.settings-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.settings-header {
  margin-bottom: 1rem;
}

.settings-title {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--text-title);
}

.settings-subtitle {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.settings-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ── Setting Card ── */
.setting-card {
  background-color: var(--bg-card);
  padding: 1rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-primary);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.setting-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.setting-label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  font-weight: 500;
  color: var(--text-secondary);
  user-select: none;
  transition: color 0.3s ease;
}

/* ── Styled Checkbox ── */
.checkbox-input {
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 4px;
  border: 1px solid var(--border-primary);
  appearance: none;
  background-color: var(--bg-input);
  cursor: pointer;
  position: relative;
  transition: all 0.15s ease-in-out;
  outline: none;
  flex-shrink: 0;
}

.checkbox-input:checked {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.checkbox-input:checked::after {
  content: "";
  position: absolute;
  left: 6px;
  top: 2px;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-input:focus-visible {
  box-shadow: 0 0 0 2px var(--color-primary-light);
}

/* ── Setting Card Body (Options) ── */
.setting-card-body {
  padding-left: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border-secondary);
  transition: border-color 0.3s ease;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.input-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color 0.3s ease;
}

/* ── Select and Numeric inputs ── */
.form-input {
  width: 100%;
  font-size: 0.875rem;
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  padding: 0.5rem;
  background-color: var(--bg-input);
  color: var(--text-primary);
  outline: none;
  transition: all 0.2s ease;
  font-family: inherit;
}

.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-light);
}

/* ── Trackers View ── */
.trackers-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* ── Empty State ── */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
}

.empty-text {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 500;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 6px -1px var(--color-primary-shadow);
  transition: all 0.2s ease;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
}

/* ── Tracker Card ── */
.tracker-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-secondary);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease,
              background-color 0.3s ease, border-color 0.3s ease;
}

.tracker-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ── Drag handle ── */
.drag-handle {
  position: absolute;
  top: 1rem;
  right: 1rem;
  display: grid;
  grid-template-columns: repeat(2, 4px);
  grid-template-rows: repeat(3, 4px);
  gap: 3px;
  opacity: 0;
  cursor: grab;
  transition: opacity 0.2s ease;
  padding: 0.25rem;
}

.drag-handle span {
  display: block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: var(--text-muted);
  transition: background-color 0.2s ease;
}

.tracker-card {
  position: relative;
}

.tracker-card:hover .drag-handle {
  opacity: 1;
}

.drag-handle:hover span {
  background-color: var(--color-primary);
}

.drag-handle:active {
  cursor: grabbing;
}

/* ── Dragging state ── */
.tracker-card.is-dragging {
  opacity: 0.4;
  transform: scale(0.98);
  box-shadow: none;
}

/* ── Drop indicator line ── */
.drag-drop-indicator {
  height: 3px;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--color-primary-hover), var(--color-primary));
  box-shadow: 0 0 8px var(--color-primary-shadow);
  margin: -0.5rem 0;
  pointer-events: none;
  animation: indicatorPulse 0.8s ease-in-out infinite alternate;
}

@keyframes indicatorPulse {
  from { opacity: 0.7; }
  to   { opacity: 1; }
}

.tracker-title {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--text-title);
  transition: color 0.3s ease;
}

.tracker-progress-info {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.progress-section {
  display: flex;
  flex-direction: column;
}

.progress-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 0.25rem;
  transition: color 0.3s ease;
}

.progress-value {
  font-size: 2.25rem;
  font-weight: 300;
  color: var(--text-primary);
  letter-spacing: -0.025em;
  font-variant-numeric: tabular-nums;
  transition: color 0.3s ease;
}

.progress-percent-symbol {
  font-size: 1.5rem;
  color: var(--text-muted);
  margin-left: 0.25rem;
  transition: color 0.3s ease;
}

/* ── Progress bar ── */
.progress-bar-container {
  height: 0.75rem;
  width: 100%;
  background-color: var(--bg-progress-track);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: 1rem;
  transition: background-color 0.3s ease;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary-hover), var(--color-primary));
  border-radius: var(--radius-full);
  transition: width 0.05s linear;
}

/* Remaining mode: bar shrinks and uses amber colour */
.progress-bar-fill.remaining-mode {
  background: linear-gradient(90deg, var(--color-remaining-hover), var(--color-remaining));
  box-shadow: 0 0 8px var(--color-remaining-shadow);
}

/* Remaining mode: track gets a subtle warm tint */
.progress-bar-container.remaining-mode {
  background-color: var(--remaining-track-bg);
}

/* When two bars are shown (both mode), tighten the gap between them */
.progress-bar-container + .progress-bar-container {
  margin-top: 0.5rem;
}